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Topic: Understanding rear shock setup (Read 885 times)

It's interesting how assumptions get made about what one understands and how one applies information. As it turns out, when I replaced my OEM shocks with Hagons, I really didn't have a complete understanding of what I was doing and why - I knew that the ride was harsh and uncomfortable, and I followed advice to try to improve things.

After a bit of back and forth, Dave Quinn recommended 18kg springs. I installed them, but I didn't really think the ride was that much improved. This last month, I tried 16kg springs, and as much as I wished for it, I couldn't honestly say I'd improved things much. Now, he's trying to help me get it sorted.

He suggested I slide what he calls the "over-stroke rubber bump stops" down to the tops of the damper bodies, to see how much travel I'm using. I didn't even notice those things were there until I changed the springs!

Anyway, I have the 16's at the softest preload setting, and I slid the bump stops down, and I rode to work - mostly little rattly bumps which try to shake your fillings loose, but a couple proper frost heaves which made me, and my back, take real notice. When I got to work, I found the stops hard up against the top of the shaft. This means that the shocks are bottoming out... which is what I figure we don't want.

On my ride home, I pushed the stops back down, and rode just a quarter mile of the little rattly bumps, and I stopped to look at the shocks again, and found the stops less than an inch from the top. So to me, it seems as if those 16 springs with soft preload aren't cutting it - I'm talking here about just me and a fairly lightweight backpack, no bags or other cargo.

So now I'm thinking about the 18's again - when I went through the motions of changing those springs, the stops were at the top of the travel, so I assumed that I didn't have a useful indicator there, but Dave says that when he builds shocks, he ships them with the bump stops pressed down against the shock body. He also says, if the buffers were at the tops of the shocks when I removed the 18kg springs, it suggests I was bottoming with them as well.

So in theory, the cause of at least some of my discomfort could be that I've never had stiff enough rear springs. Now I'm not a heavy guy - does it seem likely that at 170 pounds locked and loaded I should be bottoming out 18kg springs?

Anyway, I'm going to reinstall the 18's, drop the stops and ride a bit to see what happens. I did take a couple of longer rides last year with some luggage, without changing preload settings, which could have made the difference and bottomed out the 18's. It could be that they're perfect for me after all, travel-wise... but that means that I've still got a rough-and-tumble ride. Only my sprung solo seat has made things bearable thus far.

I think part of the issue is related to the limited suspension travel that is typical in these bikes. There isn't enough room to for the suspension to move up and down in a cushiony way. It has to do everything in just a few inches of travel. Not much spare room for "floating" on a soft spring.The purpose of the Hagons is for more suspension control and handling in sporting scenarios. They really are not for luxury car type riding, and I don't think it will be easy to find any Bullet shocks that will be like that. Not enough travel available..

I'm learning a lot which is probably very obvious to you experienced guys...

Dave Quinn has been very helpful with this. Some of his input:

Quote

You are correct, bottoming out is bad for the longevity of the shocks. Therefore, on the face of it, the springs are too soft- at least for the preload setting they are in at the time of your test. In order to get the best ride possible with progressive springs such as Hagon use, it is best not to have to preload the spring. This effectively coil binds the softest windings, which take away the suppleness of the spring. If the same adjustment was made on a single rate spring it would effectively increase the entire springs load bearing ability. So ideally you would be best off with a spring you did not need to adjust at all until you add weight (passenger/luggage or both).

The ideal situation is to end up with the buffer at or near the top of the stroke but not flattened- ie using as much of the stroke of the shock as possible without bottoming.

So I put the 18's back on, and at the softest pre-load setting, the worst bumps did bottom the shock out... but they're pretty bad frost heaves. The smaller washboard stuff pushes the bump stop to within about 1/2 an inch of bottoming out. And it's still a pretty "shocking", uncomfortable ride... basically unacceptable without my sprung solo seat. I'm riding the factory bench/log while I sort this out...

What are we talking about here as far as bottoming out goes - should it never happen? Or are we in the ballpark if it happens once every few hundred miles when the roads are particularly bad?

If it bottoms out the suspension, that is particularly jarring to the frame and to you. It would best be avoided, if possible.

What I do, and used to be common riding practice in the old days of short travel suspensions, was to just stand up on the pegs when we were able to see a big bump coming up. This evens out the weight load on front and rear, and keeps your butt out of the seat when the impact happens. All the old bikes were like this in the good old days. We managed to survive it okay.The bike isn't supposed to feel like riding on a cloud. You should feel feedback from the road and suspension.

If it bottoms out the suspension, that is particularly jarring to the frame and to you. It would best be avoided, if possible.

What I do, and used to be common riding practice in the old days of short travel suspensions, was to just stand up on the pegs when we were able to see a big bump coming up. This evens out the weight load on front and rear, and keeps your butt out of the seat when the impact happens. All the old bikes were like this in the good old days. We managed to survive it okay.The bike isn't supposed to feel like riding on a cloud. You should feel feedback from the road and suspension.

That method is still taught here in Australia, even just a few inches of your seat helps stop you getting thrown up and potentianlly making a mistake.Mind you our roads are a lot worse compaired to America, our A roads look like your B roads and our B roads and half offroad!

A simple thing you can do is lower the rear tire air pressure. Use common sense when setting it, not so low the tire deforms and squirms all over the road!. Used this on an old sportster with short travel stiff shocks and it improved the comfort a bit. Go down in small increments and test.

Ive also found a good way to avoid heavy front end shock when on a dirt road at 20mph and no way to avoid that pothole is to stand up and bounce down, then lift up on the bars as you hit it. So instead of slamming into it you sorta skip over it, the rear end still copes it but no front jarring.

Going to suggest lowering the tire pressure. I dropped mine to 18F and 24R and the ride was greatly improved over the 24/28 I'd been running. It was even comfortable! I still get a bottoming smack now and then, but overall the ride was greatly improved.Changing the fork sludge to oil made it complete! I weigh about what you do.Bare

I also installed hagons in an attempt to smooth the ride on my g5.With no spring seat I would get a lot of jarring sacks right up my spine.The most relief was found in dropping the rear tire to 24psi and the front tire to 18 psi.Anyone have a shock with a longer stroke?